Stencil attachment for typewriting machines



Jan. 5, 1932. c. GABRIELSON STENCIL ATTACHMENT FOR TYPEWRITING MACHINES Filed Aug. 26, 1929 3 Sheets-Sheet l Jan. 5, 1932. c. GABRIELSCN' 1,839,307

STENCIL ATTACHMENT FOR TYPEWRITING MACHINES Filed Au 26, 1929 3 Sheets-Sheet 2 W Emmtw Jan. 5, 1932. c. GABRIELSON STENCIL ATTACHMENT FOR TYPEWRITING MACHINES Filed Aug. 264, 1929 5 Sheets-Sheet 5 Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE CARL GABRIELSON, F SYRACUSE, NEW YORK, ASSIGNOR TO L. .0. SMITH & CORONA TYPEWRITERS INC., OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK STENCIL ATTACHMENT FOR TYIEWRITING MACHINES Application filed August 26, 1929. Serial No. 388,504.

This invention relates'to typewriting machines and is particularly concerned with that class of machine which is adapted to the typing of stencil cards. The usual stencil card for use in typewriting machines consists of a substantially rectangular frame of cardboard having the stencil sheet stretched across the central open portion thereof, it being customary to print a heading across the top of the frame for convenience in handling and filing the card.

It is an object of the present invention to provide a simple and effective means for bringing the type ribbon into play for typing a line across the top of the card frame, and for shifting the ribbon below the printing point when the impression is made on the stencil sheet.

It is also frequently desirable to provide a line of printed matter on the lower portion of the card frame, either in lieu "of or in addition to the matter typed across the top thereof, and it is therefore a further object of the present invention to provide means for prethe bottom of the card frame is in position to receive a line of typing thereon.

In the embodiment of the invention disclosed herein, a simple, compact, and effective means is provided for automatically performing the various functions mentioned above, namely the shifting of the ribbon to the pr1nting point for typing the top line on'the card frame, the removal of the ribbon from operative position for cutting the stencil, and the returning of the ribbon to the printing point for typing across the lower portion of the card frame.

A further feature of this invention resides in the complete independence of the automatic ribbon shifting mechanism and the typewriter platen. this arrangement permitting rotational feeding of the platen in an amount disproportionate to the movement of the stencil card or during'one direction of movement only of the card. A simplified arrangement for thus rotating the -platen independently of the ribbon shifting mechanism is disclosed herein and forms a part of the present invention.

senting the ribbon to the printing point when Further features and objects of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 is a front elevational view of a portion of a typewriting machine modified in accordance with the principles of the present invention to facilitate the typing of stencils, parts of the machine being broken away to clarify the disclosure;

Figure 2 is a plan view corresponding to Fig. 1;

Figures 3 to 6 inclusive, are sectional views taken on the line 3-3 of Fig. 1 and illustrating various positions of the ribbon shifting mechanism;

Figures 7 and 8 are sectional views on the line 7-7 of Fig. 1 and showing the platen feed mechanism in different positions;

Figures 9 and 10 are sectional views corresponding to Figs. 5 and 6 of a modified form of the device and Figure 11 is a sectional view through the card holder taken approximately on the line 1111 of Figure 1.

The preferred embodiment of the present invention is illustrated in Figs. 1 to 8 of the drawings in which suificient structure has been disclosed to enable one skilled in the art to practice the invention, the conventional parts of the typewriting machine being omitted for the sake of clearness. A rotatable platen shaft 10, adapted to be retained in the usual standards by platen locking springs 11, carries a platen 12, the latter being mounted on the shaft 10 and preferably rotatable with respect thereto.

Stationary card holding guides 14:, mounted on the typewriting machine frame in any suitable manner, are disposed on either side of, the platen 12, and are preferably rooved as at 15 to receive and support a can? holder 16, adapted to carry a conventional stencil card 17, for line-spacing movement in front of the platen. Card feed segments 19, secured to the platen shaft 10 on either side of the platen, are arranged to mesh with racks 21 integral with or secured to the card holder to reciprocate the latter in the well-known manner in response to line-spacing movements of the platen shaft. A knob or handle 20, secured to the platen shaft and augmented by the usual line-spacing mechanism, serves to actuate the platen shaft 10 for this purpose.

It is desirable to provide means for gradually advancing the platen during the operation of the machine so that fresh portions of the platen are successively brought to the printing point for avoiding excessive wear of any one portion of the platen. Further advantages arising from slowly advancing the platen are set forth in my copending application Serial No. 355,897, filed r pril 17, 1929, in which the platen serves to effect the gradual feed of a ribbon interposed between the stencil card and the platen for rendering the characters cut in the stencil clearly visible, and it will be understood that such an arrangement may be incorporated in the present construction, if desired.

Referring to Figs. 7 and 8, in which one form of operating mechanism for the platen is disclosed, it will be seen that this mechanism is extremely compact and simple and consists primarily of a cam 22 secured to the platen shaft 10, a toothed member 23 secured to the platen, and an element 24 for transmitting movement of the cam 22 to the toothed member 23. The element 24 is preferably pivoted at 25 to the adjacent card frame guide, and is provided with a working face 26 of such configuration that when the cam is moved from the position shown in Fig. 7 to that of Fig. 8, the element 24 will be displaced sli htly about the pivotal axis V 25 thereof. spring 27 serves to maintain the working face of the element 24 in engagement with the cam, and a pawl 28, pivoted to the element 24, engages the toothed member 23 to effect rotation of the latter in one direction when the element 24 is displaced as described. Movement of the member 23 and platen 12 in the reverse direction may be prevented by the provision of a spring pawl 29, or by equivalent retaining means. The operation of the mechanism just described will now be apparent, it being observed that the platen is very gradually rotated as the platen shaft is moved for line-spacing the stencil card, and that the extent of rotation of the platen may be controlled by altering the configuration of the working face 26 of the ele ment 24.

A ribbon carrier 30 is supported in the usual manner for reciprocatory movement in front of the platen to carry the ribbon to and from the printing point. In the present embodiment of the invention, the usual ribbon vibrating mechanism is dispensed with, and the ribbon is shifted to and from the printing point by the mechanism about to be described;

As shown in detail in Figs. 9 and 10 of the drawings, a cam 31 is secured to the platen shaft adjacent one end of the platen and preferably at that end of the platen which is remote from the cam 22. A shaft 35, extending transversely of the machine and supported in the machine frame by brackets 36, is provided with arms 37, adjacent either end thereof, one of said arms having a follower portion 38 for cooperative engagement with the cam.

The arms 37 are connected adjacent the free ends thereof by an element 40 which in turn cooperates with the ribbon carrier to shift the latter into and out of operative position. This connection may be conveniently effected in the manner shown in the drawings in which the element 40 extends above a pair of inwardly projecting tongues 42 formed integrally with the carrier and beneath a roller 43 supported on the carrier. Springs 44 may be provided on the shaft 35 to maintain the ribbon carrier and ribbon normally in elevated or operative position with the follower portion 38 in engagement with the cam 31. It is evident that cams may be provided adjacent both ends of the platen for coo-peration with both arms 37, if desired, although such an arrangement is-ordinarily not necessary and results in unduly increasing the space required for the operating parts. It is furthermore obvious that the configuration of the cam 31 will determine the point in the line-spacing movement of the stencil card at which the ribbon is elevated. For instance, this cam may be constructed to permit elevation of the arms 37 and the associated ribbon carrier when the stencil card is in the lower as well as the upper position, so that typed anism is shown in various positions, it will 7.

be noted that the arm 37 having the follower portion 38 has been slightly modified. An element 46, pivoted to the arm 37 and having the "forward pivotal movement thereof limited by the provision of a stop 47, serves to engage the working face of the cam. A light spring 48, preferably acting between the arm 37 and the element 46, normally urges the latter forwardly, as will be apparent from the drawings.

The sequence of operations of this modi fied arrangement is substantially as follows:

When the mechanism is in position to receive afresh card as shown in Fig. 3, the

ribbon carrier 30 occupies its upper or operative position, the element 46 engaging the depressed portion of the cam 31. As the platen shaft is rotated in a counterclockwise direction to depress the card holder and stencil card, the raised portion of the cam 31 will move the element 46 to the right by reason of the frictional engagement of these parts, against the action of the light spring 48, the position which the element 46 assumes being indicated in Fig. 4. It will be noted that the ribbon carrier is still elevated and that the ribbon consequently remains at the printing point during the lowering of the card holder.

When the card holder reaches its lowest position, as indicated in Fig. 5, the raised portion of the cam 31 has been rotated sufficiently far to permit the element 46 to return to its original position in contact with the stop 47 under the influence of the spring 48, and the ribbon is not shifted during this operation, the element 46 engaging the depressed portion of the cam 31. The parts now occupy a position which permits the typing of a line on the upper portion of the card frame.

The platen shaft is now rotated in a clockwise direction to elevate the card holder for line-spacing the card. As the stencil frame is elevated, the raised portion of the cam 31 acts through the element 46 to depress the arm 37 and to thereby remove the ribbon from the printing point, thus permitting the cutting of the stencil in the stencil sheet which occupies the central portion of the card frame. During the upward movement of the card holder and stencil card, the element 46 is retained in contact with the, pin 47 as indicated in Fig. 6. When the stencil card is sufficiently elevated to present the lower portion of the stencil frame at the printing point, the parts occupy the position illustrated in Fig. 3, the element 46 again engaging the depressed portion of the cam 31, so that the ribbon is simultaneously shifted to the printing point for typing a line on the lower portion of the card frame. The card may be then removed, a fresh card inserted, and the operation re eated.

It will be noted that the efigct of this modified arrangement is to retain the ribbon in operative position during the downward movement of a fresh card preliminary to typing thereon. In the arrangement disclosed in Figs. 9 and 10, the ribbon carrier and ribbon are unnecessarily reciprocated during this downward movement of the stencil card. It will thus be evident that the modified arrangement avoids unnecessary wear of the b ribbon carrier and its support, and while this wear is, of course, very slight, due to the small weight of the carrier, it is found that the repeated unnecessary reciprocation of this carrier actually gives rise to an appreciable amount of wear. The modified construction has the further advantage of avoiding unnecessary movement of visible parts which might tend to annoy the operator by attracting attention thereto.

It will be understood that various further modifications of the, arrangement described herein for the purpose of illustration may be made without departing from the principles of the present invention, and that the invention contemplates all such alterations in the constructional details as may fall within the spirit and scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is: v

1. In a typewriting machine, the combination with a platen, of a card holder adapt ed to receive a stencil card therein 'movable across the platen for line-spacing the card, a ribbon carrier arranged to support a rib: bon in ineffective position during thecutting of the stencil, and means operable on movement of the card holder to a position for typing on the lower portion of the stencil card for shifting the ribbon carrier and the ribbon carried thereby to effective position.

nation with a platen, of a card holder adapted to receive a stencil card therein movable in front of the platen, means for imparting line-spacing movement to the card-holder and associated card, a ribbon carrier for supporting a ribbon away from the printing point during the cuttin of the stencil, and means operable by said rst named means on movement of the holder and card to a position for typing on the lower portion 'of the card for shifting the ribbon carrier to present the ribbon to the printing point.

3. In a typewriting machine, the combination with a platen, of a card holder adapted to receive a stencil card therein movable across the platen, means for imparting linespacing movement to said card holder and associated card, a ribbon carrier for normally supporting a ribbon in inoperative position, and means actuated directly from said first named means for shifting the ribbon carrier and ribbon to operative position when said card holder and associated card occupy a predetermined position.

4.'In a typewriting machine, the combination with a platen and platen shaft, of a card holder adapted to receive a stencil card therein for line spacing movement adjacent the platen, a ribbon carrier shiftable to place a ribbon in operative or inoperative positions, means connecting said shaft and card holder for effecting line-spacing movement of the latter, and means on said shaft for determining the position of said ribbon carrier and the associated ribbon.

5. In a typewriting machine, the combination with a platen, of a platen shaft, a card holder adapted to receive a stencil card therein movable to line-space the stencil card, a ribbon carrier adjacent the stencil and shiftable towcarrythe ribbon to operative and inoperative positions, means associated with said shaft and positioned at one side of said platen for imparting line spacing movement to the card holder and stencil card, and means associated withsaid shaft and positioned at the other side of said platen for effecting shifting of the ribbon carrier and ribbon.

6. In a typewriting machine, the combination with a platen, of a platen shaft, 2. card holder adapted to receive a stencil card, said card holder being movable across the platen to line-space the card, means associated with said platen shaft for moving said card holder, a ribbon carrier adapted to carry a ribbon to and from the printing point, and a cam on said shaft operatively connected to said carrier to effect shifting movement of said ribbon carrier and ribbon.

7. In a typewriting machine, the combination with a platen, of a platen shaft, a card holder adapted to receive a stencil card, said card holder being movable across the platen to line-space the card, means associated wit-h said platen shaft for moving said card holder, a ribbon carrier adapted to carry a ribbon to and from the printing point, a cam on said shaft, and a lever connecting said cam and ribbon carrier, whereby the position of said ribbon carrier and ribbon is definitely related to the position of said card holder and associated stencil card.

8. In a typewriting machine, the combination with a platen shaft, of a platen rotatable with respect to said shaft, a cam on said shaft, means operated by said cam for effecting gradual rotation of said platen in one direction, and a workholder operable by said shaft independently of said platen.

9. In a typewriting machine, the combination with a platen shaft, of a platen rotatable with respect to said shaft, a cam on said shaft, a lever engaged by said cam and having a one-way driving connection with said platen to eifect gradual rotation of the latter on movement of said shaft in one direction, and a workholder operable by said shaft independently of said platen.

10. In a typewriting machine, the combination with a platen, of a platen shaft, a card holder adapted to receive a stencil card, said card holder being movable across the platen to line-space the card, means associated with said platen shaft for moving said card holder, a ribbon carrier adapted to carry a ribbon to and from the printing point, a cam on said shaft, a lever associated with said ribbon carrier for shifting the carrier and ribbon, and a. follower engaging said cam and movable to either of two positions on said lever by rotation of the cam in opposite directions, said lever and follower being operable by said cam in one of the said positions only of the latter to remove the ribbon from the printing point for cutting the stencil.

11. In a typewriting machine, the combination with a platen, of a platen shaft, a card holder adapted to receive a stencil card, said card holder being movable across the platen to line-space the card, means associated with said platen shaft for moving said card holder, a ribbon carrier adapted to carry a ribbon to and from the printing point, means for biasing said carrier and ribbon to effective position at the printing point, a cam on said shaft, a lever associated with said ribbon carrier, a follower pivoted on said lever, engaging said cam, and movable to either of two positions with respect to said lever on rotation of said cam in opposite directions, said lever and follower being operable by said cam in one of the said positions only of the latter to shift the ribbon carrier and ribbon against the action of said biasing means.

12. The combination recited in claim 11 in which the active surface of the cam is provided with spaced depressed portions and a raised portion intermediate thereof, whereby the ribbon will be retained at the printing point by said biasing means during the entire rotational movement of the cam in one direction and will be shifted from the printing oint during an intermediate portion only of the rotational movement of the cam in the opposite direction.

In testimony whereof I hereunto affix my signature.

CARL GABRIELSON. 

